Been reading a lot of stuff about Limewire and firewalls, in the user guide, tips of the day, these forums, etc. and I still don't get it completely. I'm hoping somebody can wrap it up such that an experienced, yet non-technical, LW user can understand. As far as I can tell I am able to connect and dl regardless of whether I'm behind a firewall or not. I have no obvious problems, except that search results are wayyyyyyyyy worse than they used to be in earlier times.

First, a summary of my questions:
1. If I can operate behind a firewall, do I still need to open a Gnutella/Limewire port?
2. Are my crappy search results due to being behind a firewall?
3. Does opening a port weaken the general security of my computer?

1. I read somewhere that Limewire sometimes can operate from behind a firewall, and it *seemed* to imply that as long as you can connect and download then it's cool, you don't have to worry about messing around w/ your firewalls. That is the case w/ me. I have the brick wall/globe icon but I can connect and dl.

I have tried working with all services and ports closed as per the OSX Tiger default, and also with the Gnu/LW port opened. I haven't done any serious comparisons of LW's performance in these two scenarios, but it seems to work pretty much the same, both ways. Dl's are pretty fast. Should I open the Gnutella/Limewire port anyway?

2. I have not experimented enough to tell whether my LW search results are any better with the Gnu/LW port open, but I can tell you that either way the search results are much worse than they used to be several months, or maybe even a few years ago (I'm pretty vague remembering the time scale--don't use LW much any more because of the crappy search results). Can working from behind the firewall hurt search results?

Sorry, I'm not sure how many things have changed in my setup since my search results used to be so much better, but some things I'm sure of are:
- Changed from Earthlink dialup to AT&T DSL, with Siemens Speedstream 4100 modem.
- Occasional OS updates over time. Currently up to OSX 10.4.9
- Upgraded LW when I moved from Classic to OSX. This may be when things started to go south, *IF* I remember right. That's a big IF though. Currently using LW 4.12.3.
- Music record industry began cracking down, flooding with bogus files, and other tactics. But my poor search results seem to be across the board, not limited to searches that the music industry is trying to block.
- Bogus commercial search results have increased dramatically, to where they dominate many of my searches. But maybe I'm digressing here--sorry.

3. In general, security experts tell lay people "you should always use firewalls". Security concerns are very important to me, but I'm ignorant about the architecture of firewalls and ports. Does opening the Gnu/LW port lessen the security of my computer in any way? Does opening this port mean that as far as Gnutella is concerned I don't have a firewall, and/or does it make me more vulnerable to any bad things, either via Gnutella or via any other pathways?

G4
OSX 10.4.9
Firewalls: standard OSX firewall on, all services and ports stopped, closed.
Limewire 4.12.3
Java 1.4.2 with J2SE 5.0 Release 1 update, and Java Prefs Runtime Settings set with J2SE 5.0 on top. However I just installed the J2SE 5.0 update today so I don't know yet if anything has improved because of it.
DSL from AT&T, with Siemens Speedstream 4100 modem
I'm only a leaf node but I get a lot of incoming searches for things totally unrelated to anything on my computer.